Today, a bunch of new instances appeared in the top of the user count list. It appears that these instances are all being bombarded by bot sign-ups.

For now, it seems that the bots are especially targeting instances that have:

  • Open sign-ups
  • No captcha
  • No e-mail verification

I have put together a spreadsheet of some of the most suspicious cases here.

If this is affecting you, I would highly recommend considering one of the following options:

  1. Close sign-ups entirely
  2. Only allow sign-ups with applications
  3. Enable e-mail verification + captcha for sign-ups

Additionally, I would recommend pre-emptively banning as many bot accounts as possible, before they start posting spam!

Please comment below if you have any questions or anything useful to add.

Update: on lemm.ee, I have defederated the most suspicious spambot-infested instances.

To clarify: this means small instances with an unnaturally fast explosion in user counts over the past day and very little organic activity. I plan to federate again if any of these instances get cleaned up. I have heard that other instances are planning (or already doing) this as well.

It’s not a decision I took lightly, but I think protecting users from spam is a very important task for admins. Full info here: https://lemm.ee/post/197715

If you’re an admin of an instance that’s defederated from lemm.ee but wish to DM me, you can find me on Matrix: @sunaurus:matrix.org

  • PriorProject@lemmy.world
    3·
    2 years ago

    They can do this, and it is cat and mouse. But…

    1. It generally costs money to stand up an instance. It often requires a credit-card, which reduces anonymity. This will dissuade many folks.
    2. A malicious instance can be defederated, so it might not be all that useful.
    3. People can contact the security team at the host providing infra/internet to the spammer. Reputable hosts will kill the account of a spammer, which again is harder to duplicate if the host requires payment and identity info.
    4. Malicious hosts that fail to address repeated abuse reports can be ip-blocked.
    5. Eventually Lemmy features can be built to protect against this kind of thing by delaying federation, requiring admin approval, or shadow -banning them during a trial period.

    Email has shown us that there’s a playbook that kind of works here, but it’s not easy or pleasant.

    • katie@lemmy.tillicumnet.com
      1·
      2 years ago

      I’ve been thinking about this as well. As a user of a private instance, I would be absolutely fine with a “federation application” much like user registration is currently.